I wanted to build a "simple" plane as my first, hence the -12. I'm getting my PPL currently, so LSA is not required.

I'll probably design my own basic VFR panel anyway, so I'm already signing up for additional work, and it's a challenge that I like.

From FlyCorvair.com:
"The engine weighs 225 pounds ready to run. This is effectively the same as a Continental O-200. Itís installed weight is 35 pounds more than a 912 Rotax, 25 pounds more than a Jabaru 3300. The Corvair is 40 pounds lighter than a Lycoming O-235. 3,000 cc Corvairs are slightly lighter than 225 lbs. because we have special cylinders made for them which make these engine 5 pounds lighter."

Not sure where you got the Rotax weight # but it is a bit on the high side.
Installed weight for a 912 is closer to 170 Lb so that would put the Corvair 55 lbs heavier. That would be rather difficult to deal with.
At least one RV-12 was built with an O-200 and once the builder got to the weighing and C.G. calculation process, he ended up removing it and installing a Rotax.

__________________Any opinions expressed in this message are my own and not necessarily those of my employer.

I would not recommend a Corvair engine for the RV-12 with the weight and length issues you will have to deal with. I installed the Viking 110 and it added two years to my build time not to mention 50 extra pounds over a typical 912 powered RV-12 empty weight. Forward CG issues required moving the dual batteries and dual fuel pumps behind the baggage compartment bulkhead to get weight off the nose wheel.

If I were starting an EAB RV-12 today and wanted to do my own engine package, I would look for a used 912 ULS ($6K-$9K) to build up with an EFI and maybe a performance camshaft for a few more HP. If you want a Corvair powered aircraft, scratch the RV-12 off the list.

I'd rather build something quicker and easier, less time not being with my 4 year old son, which he could start helping with In a few years.

If you finish the plane one day you'll want to take your son flying with you.

On that basis I wouldn't be making engine purchase decisions working backwards from a desire to save money. I'd be making that decision based purely on the most reliable product available. And in the case of the RV12 that happens to be the Rotax provided by Vans.

I am not sure if your are talking about a Corvair with a reduction drive or direct drive. If direct drive, remember the corvair’s thrust bearing is at the back of the motor and was not designed to carry a prop, just a flywheel. The crank is not counter balance and is designed to have a flexible coupling. Please think of the others who will be trusting you to build a safe plane.

Most Corvairs are flying direct drive with a 5th bearing to handle prop loads. Many are flying with alloy steel billet cranks as well. They work just fine in aircraft these days using a fairly proven recipe based on hard lessons from the past.

Hard as it may be for some to understand, some folks want something different than another cookie cutter RVX. Power to the true experimenter- as long as they understand the extra work and possible risk involved. Most people who go with the tried and true will never feel the satisfaction of making something different work well.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.